cooling Lexus GS450h 2018 Owner's Manual / LEXUS 2018 GS450H OWNER'S MANUAL (OM30G62U)

681-2. Hybrid system
GS450h_OM_OM30G62U_(U)
■Conditions in which the gasoline engine may not stop
The gasoline engine starts and stops automati cally. However, it may not stop automati-
cally in the following conditions:
●During gasoline engine warm-up
●During hybrid battery (traction battery) charging
●When the temperature of the hybrid battery (traction battery) is high or low
●When the heater is switched on
■Charging the hybrid battery (traction battery)
As the gasoline engine charges the hybrid battery (traction battery), the battery does not
need to be charged from an ou tside source. However, if the vehicle is left parked for a
long time the hybrid battery (traction batter y) will slowly discharge. For this reason, be
sure to drive the vehicle at least once every few months for at least 30 minutes or 10
miles (16 km). If the hybrid battery (traction battery) beco mes fully discharged and you
are unable to start the hybrid system, contact your Lexus dealer.
■Charging the 12-volt battery
→ P. 459
■After the 12-volt battery has discharged or when the terminal has been removed and
installed during exchange, etc.
The gasoline engine may not stop even if the vehicle is being driven by the hybrid battery
(traction battery). If this continues fo r a few days, contact your Lexus dealer.
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sound or vibration even though the vehicle is able to move with
the “READY” indicator is illuminated. For sa fety, apply the parking brake and make sure
to shift the shift lever to P when parked.
The following sounds or vibrations may occu r when the hybrid system is operating and
are not a malfunction:
●Motor sounds may be heard from the engine compartment.
●Sounds may be heard from the hybrid battery (traction battery) behind the rear seats
when the hybrid system starts or stops.
●Relay operating sounds such as a snap or so ft clank will be emitted from the hybrid bat-
tery (traction battery), behind the rear se ats, when the hybrid system is started or
stopped.
●Sounds from the hybrid system may be heard when the trunk lid is open.
●Sounds may be heard from the transmission wh en the gasoline engine starts or stops,
when driving at low spee ds, or during idling.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerative braking when the brake pedal is depressed
or as the accelerator pedal is released.
●Vibration may be felt when the ga soline engine starts or stops.
●Cooling fan sounds may be heard from the air intake vents on the both sides of the rear
seatback.

701-2. Hybrid system
GS450h_OM_OM30G62U_(U)
Hybrid system precautions
The illustration is an example for explanation and may differ from the actual item.
There are air intake vents on the both
sides of the rear seatback for the pur-
pose of cooling the hybrid battery
(traction battery). When the air intake
vents are blocked, battery operations
will be restricted, leading to poor fuel
economy.
Take care when handling the hybrid system, as it is a high voltage system
(about 650 V at maximum) as well as contains parts that become extremely
hot when the hybrid system is operating. Obey the warning labels attached to
the vehicle.
Warning label
Power control unit
Electric motor (traction motor)
Hybrid battery (traction battery) Service plug
High voltage cables (orange)
Air conditioning compressor
Hybrid battery (traction battery) air intake vents
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GS450h_OM_OM30G62U_(U)
2594-5. Using the driving support systems
4
Driving
Sport mode•SPORT S mode
Assists acceleration response by co ntrolling the transmission and engine.
When not in SPORT S mode and the driving mode select switch is turned to the
right, the “SPORT S” indicator comes on in the multi-information display, and the
Hybrid System Indicator changes to the tachometer. ( →P. 93)
•SPORT S+ mode
Helps to ensure steering performanc e and driving stability by simultane-
ously controlling the steering and suspension in addition to the hybrid sys-
tem. Suitable for sporty driving.
When in SPORT S mode and the driving mode select switch is turned to the right,
the “SPORT S+” indicator comes on in the multi-information display.
■Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air condi-
tioning system to enhance fuel efficiency. To improve air conditioning performance, per-
form the following operations:
●Turn off eco air conditioning mode (→P. 289)
●Adjust the fan speed ( →P. 288)
●Turn off Eco drive mode
■Automatic operation of the seat heater during Eco drive mode
Eco drive mode controls the heating operatio n and fan speed of the air conditioning sys-
tem to enhance fuel efficiency. If the driving mode select switch is switched to Eco drive
mode in cold temperatures, the seat heater will be automatically operated to assist heat-
ing performance.
■Automatic deactivation of sport mode and customized mode
If the power switch is turned off after driv ing in sport mode or customized mode, the
drive mode will be changed to normal mode.
■Driving mode pop-up display
When the driving mode is changed, the sele cted driving mode will be temporarily dis-
played on the side display. ( →P. 285)
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GS450h_OM_OM30G62U_(U)
4-6. Driving tips
Hybrid vehicle driving tips
◆Using Eco drive mode
When using Eco drive mode, the torque corresponding to the accelerator
pedal depression amount can be generated more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system (heating/
cooling) will be minimized, improving the fuel economy. ( →P. 258)
◆Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicate of Hybrid System
Indicator within Eco area. ( →P. 92)
◆Shift lever operation
Shift the shift lever to D when stopped at a traffic light, or driving in heavy traf-
fic etc. Shift the shift lever to P when parking. When using the N, there is no
positive effect on fuel consumption. In the N, the gasoline engine operates but
electricity cannot be generated. Also, wh en using the air conditioning system,
etc., the hybrid battery (tractio n battery) power is consumed.
◆Accelerator pedal/brake pedal operation
●Drive your vehicle smoothly. Avoid ab rupt acceleration and deceleration.
Gradual acceleration and deceleration will make more effective use of the
electric motor (traction motor) withou t having to use gasoline engine power.
●Avoid repeated acceleration. Repeated acceleration consumes hybrid bat-
tery (traction battery) po wer, resulting in poor fuel consumption. Battery
power can be restored by driving with the accelerator pedal slightly released.
◆When braking
Make sure to operate the brakes gently and in a timely manner. A greater
amount of electrical energy can be regenerated when slowing down.
For economical and ecological driving, pay attention to the following points:

GS450h_OM_OM30G62U_(U)
2895-2. Using the air conditioning system and defogger
5
Interior features
Adjust the left-hand side temperature setting
Select the air flow to the feet an d operate the windshield defogger
Adjust the fan speed setting
Select the air flow mode
* (the front seats)
Function on/off indicators on the option control screen
Display the option control screen ( →P. 290)
Adjust the right-hand side temperature setting
Set eco air conditioning mode ( →P. 296)
Air conditioning and heater output is limited to prioritize fuel economy.
Adjust the temperature for the driver ’s and front passenger’s seats sepa-
rately (DUAL mode) ( →P. 288)
Set cooling and dehumidification function on/off
Select to set automatic mode on/off
Select the air flow mode
* (the left-hand side)
Select the air flow mode
* (the right-hand side)
Display the rear air conditioning operation screen ( →P. 291)
Adjust the temperature for the driver’s, front passenger’s and rear seats
(→ P. 298) separately (3-ZONE mode) ( →P. 288)
To adjust or select settings, move the Remote Touch knob to select the
screen button, and then press the Re mote Touch knob or the “ENTER” but-
ton of Remote Touch to enter the selected function.
Control screen
Without rear air conditioning systemWith rear air conditioning system
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GS450h_OM_OM30G62U_(U)
2915-2. Using the air conditioning system and defogger
5
Interior features
■Side display
Adjust the left-hand side temperature setting
Select the air flow mo de (the front seats)
Adjust the fan speed setting
Adjust the right-hand side temperature setting
Adjust the temperature for the driver’s and front passenger’s seats separately
(DUAL mode) ( →P. 288)
Set cooling and dehumidification function on/off
Select to set automatic mode on/off
Select the air flow mode (the left-hand side)
Select the air flow mode (the right-hand side)
Adjust the temperature for the driver ’s, front passenger’s and rear seats
( → P. 298) separately (3-ZONE mode) ( →P. 288)
■Rear air conditioning control screen (with rear air conditioning system)
Adjust the rear seat temperature
setting
Disabling the switches on the rear
armrest
Turn the fan off (rear seat)
Select to set automatic mode on/
off (rear seat)
Without rear air conditioning systemWith rear air conditioning system
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GS450h_OM_OM30G62U_(U)
2955-2. Using the air conditioning system and defogger
5
Interior features
■Adjusting the position of and opening and closing the air outlets
Direct air flow to the left or right, up or down.
Turn the knob to open or close the vent.
■Registering air conditioning settings to electronic keys
●Unlocking the vehicle using an electronic key and turning the power switch to ON
mode will recall that ke y’s registered air conditioning settings.
●When the power switch is turned off, the cu rrent air conditioning settings will automati-
cally be registered to the electronic key that was used to unlock the vehicle.
●The system may not operate correctly if more th an one electronic key is in the vicinity or
if the smart access system with push-button start is used to unlock a passenger door.
●Settings for the electronic key and the corresponding door can be changed. Contact
your Lexus dealer.
■Using automatic mode
Fan speed is adjusted automatically accordin g to the temperature setting and the ambi-
ent conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow immediately
after is pressed.
Cool air may blow around the upper body even when the heater is on due to sunlight.
■Fogging up of the windows
●The windows will easily fog up when the humidi ty in the vehicle is high. Turning “A/C” on
will dehumidify the air from the outlets and defog the windshield effectively.
●If you turn “A/C” off, the windows may fog up more easily.
●The windows may fog up if the recirculated air mode is used.
■Outside/recirculated air mode
●When driving on dusty roads such as tunnels or in heavy traffic, set the outside/recircu-
lated air mode button to the recirculated air mode. This is effective in preventing out-
side air from enteri ng the vehicle interior. During cooling operation, setting the
recirculated air mode will also cool the vehicle interior effectively.
●Outside/recirculated air mode may automa tically switch depending on the tempera-
ture setting or the inside temperature.
Front center outlets and front side
outletsRear seat outlets
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GS450h_OM_OM30G62U_(U)
5-2. Using the air conditioning system and defogger
■When the outside temperature exceeds 75°F (24°C) and the air conditioning system
is on
●In order to reduce the air co nditioning power consumption, the air conditioning system
may switch to recirculated air mode automa tically. This may also reduce fuel consump-
tion.
●Recirculated air mode is selected as a default mode when the power switch is turned
on.
●It is possible to switch to outside air mode at any time by pressing .
■Automatic mode for air intake control
In automatic mode, the system detects exhaust gas and other pollutants and automati-
cally switches between outside air and recirculated air modes.
When the dehumidification function is off, and the fan is operating, turning automatic
mode on will activate the dehumidification function.
■Operation of the air conditioning system in Eco drive mode
In the Eco drive mode, the air conditioning sy stem is controlled as follows to prioritize
fuel efficiency:
●Engine speed and compressor operation controlled to restrict heating/cooling capac-
ity
●Fan speed restricted when automatic mode is selected
To improve air conditioning performanc e, perform the following operations:
●Turn off eco air conditioning mode
●Adjust the fan speed
●Turn off Eco drive mode ( →P. 258)
■Eco air conditioning mode
When Eco drive mode is selected using the drive mode select switch, eco air condition-
ing mode turns on.
When a drive mode other than Eco drive mo de is selected, eco air conditioning mode
may turn off.
■When the S-FLOW mode operates
If air flows to the driver’s seat only, the te mperature setting for the front passenger’s seat
is not displayed.
■When the outside temperature is low
The dehumidification function may not operate even when “A/C” on the option control
screen is selected.
■Ventilation and air conditioning odors
●To let fresh air in, set the air conditioning system to the outside air mode.
●During use, various odors from inside and outside the vehicle may enter into and accu-
mulate in the air conditioning system. This may then cause odor to be emitted from the
vents.
●To reduce potential odors from occurring:
• It is recommended that the air conditioning system be set to outside air mode prior
to turning the vehicle off.
• The start timing of the blower may be dela yed for a short period of time immediately
after the air conditioning system is started in automatic mode.

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GS450h_OM_OM30G62U_(U)
6-3. Do-it-yourself maintenance
WARNING
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energize d. To avoid death or serious injury, observe
the following precautions.
■When working on the engine compartment
●Make sure that the “POWER ON” on the multi-information display and the
“READY” indicator are both off.
●Keep hands, clothing and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, power co ntrol unit, radiator, exhaust manifold, etc.
right after driving as they may be hot. Oil and other fluids may also be hot.
●Do not leave anything that may burn easily, such as paper and rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flamma-
ble.
■When working near the electric cooling fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fans may automatically start to
run if the air conditioning is on and/ or the coolant temperature is high. ( →P. 359)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting in
your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner f ilter removed may cause excessive engine wear due to dirt
in the air.

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GS450h_OM_OM30G62U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Engine compartment
■12-volt battery
→ P. 362
Engine oil level dipstick
(→P. 355)
Engine coolant reservoir (→P. 358)
Engine oil filler cap (→ P. 356)
Power control unit coolant
reservoir ( →P. 358) Brake fluid reservoir
(→P. 360)
Fuse box ( →P. 384)
Washer fluid tank ( →P. 361)
Electric cooling fans
Condenser ( →P. 359)
Radiator (→ P. 359)1
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